The efficient separation of pentlandite from serpentine remains a challenging issue in the processing of nickel sulfide ores. In this study, selective magnetic coating-magnetic separation was employed to separate the pentlandite from serpentine with adding NaOL as a coagulant, which is different from the conventional flotation. The results indicate that it was very effective for their separation. Furthermore, the role of NaOL in the separation was evaluated in detail by means of adsorption tests, zeta potential measurements, Fourier transform infrared (FTIR) spectra analyses, solution chemistry calculations X-ray photoelectron (XPS) spectra analyses, and scanning electron microscopy-energy dispersive spectra (SEM-EDS) analyses. It turns out that NaOL can adsorb selectively onto the surfaces of pentlandite and magnetite through the Ni and Fe sites (serpentine was pre-depressed by sodium hexametaphosphate (NaHMP)) and form the hydrophobic surfaces between the two minerals. As a result, the pentlandite surface was selectively coated by the magnetite fines and then was separated from serpentine using magnetic separation. Therefore, our results provide an alternative technology for their separation and exhibit great potential for further study and applications. (C) 2019 Elsevier B.V. All rights reserved.